The present, community-based study aims to assess if an ORS with Lactobacillus reuteri DSM 17938 and zinc can be superior or equivalent to ORS without probiotic and zinc in reducing the duration of acute gastroenteritis in children aged 6-36 months, with no, mild or moderate dehydration when introduced early (within 48 hours) after the start of gastroenteritis associated diarrhoea in an out-patient setting.